There's no minimum length, and there's no minimum number of articles a day that you have to post, nor even a minimum number of pages on a website. In most cases, quality is better than quantity. Our algorithms explicitly try to find and recommend websites that provide content that's of high quality, unique, and compelling to users. Don't fill your site with low-quality content, instead work on making sure that your site is the absolute best of its kind.

It is about the quality of the content, not the length of the content.

Then someone else comes in and says "if write short length content may I penalize in future, Ii need straight forward answer." John Mueller responds:

If you write low-quality content (short or long), then yes, our algorithms and even our manual webspam team may choose not to trust your website.

So again, it is not about content length, it is about content quality.